test_manager_lib/
utilities.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use futures::prelude::*;
6use futures::StreamExt;
7use log::info;
8
9/// Convert iterator fidl method into stream of events.
10/// ie convert
11/// fidl_method() -> Future<Result<Vec<T>, E>>
12/// to
13/// Stream<Item=Result<T, E>>
14pub fn stream_fn<F, T, E, Fut>(query_fn: F) -> impl Stream<Item = Result<T, E>>
15where
16    F: 'static + FnMut() -> Fut + Unpin + Send + Sync,
17    Fut: Future<Output = Result<Vec<T>, E>> + Unpin + Send + Sync,
18{
19    futures::stream::try_unfold(query_fn, |mut query_fn| async move {
20        Ok(Some((query_fn().await?, query_fn)))
21    })
22    .try_take_while(|vec| futures::future::ready(Ok(!vec.is_empty())))
23    .map_ok(|vec| futures::stream::iter(vec).map(Ok))
24    .try_flatten()
25}
26
27/// A struct which logs a set string when it drops out of scope.
28pub struct LogOnDrop(pub &'static str);
29
30impl std::ops::Drop for LogOnDrop {
31    fn drop(&mut self) {
32        info!("{}", self.0);
33    }
34}
test_manager_lib/utilities.rs

test_manager_lib/
utilities.rs
